Process of manufacturing 1&#39;-chloro-1-methylnaphthalene



Patented May 23, 1933 GUSTAV REDDELIEN,

OF LEIPZIG, AND MANY, ASSIG-NORS T6 GENERAL ANILINE CORPORATION OF DELAWARE HAN S LAN GE,

013 DESSAU IN ANHAL'I, GER- WORKS, ENG, OF NEW YORK, N. Y., A

PROCESS OF IVIANUFAGTURING 1-CHLORO-l-METHYLNAPHTHALENE No Drawing. Application filed December 23, 1929, Serial No. 416,206, and in Germany January 12, 1929.

Our present invention relates to a new process of manufacturing l-chloro-1-methylnaphthalene of the formula According to our invention, naphthalene is transformed into l-chloro-l-methylnaphthalene in simple manner and With a good yield by mixing crystallized naphthalene in an aqueous suspension with a molecular amount formaldehyde and with concentrated hydrochloric acid and by stirring the mixture while cautiously heating. Preferably, the concentration of acid is maintained at a sufiicient degree by simultaneously introducing gaseous hydrogen urthermore, We prefer to carry chloride. 1* out our new process at a temperature of about 60 C. to about 70 (1; under these 95 conditions yields of more than 60 per cent of the theoretical amount are easlly obtained, however, the reaction temperature may be varied within certain limits and good results even are obtained at temperatures between 40 to about 100 C.

The reaction may be illustrated by the following equation:

+HCI+O=OH= +H2o.

In contradistinction to other known processes we neither use an organic solvent nor a condensing agent nor apolymerized formaldehyde. Th e l-chloro-l-methylnaphthalene is a valuable intermediate product, for instance, in the manufacture of synthetic dyes.

The following example illustrates the invention without limiting it, the parts being by weight Example.-7 68 parts of pulverized naphthalene are introduced into 750 parts of an hydrochloric acid. The mixture is heated to about to about C. While stirring and introducing hydrogen chloride. After 10 55 hours, the oil floating on the surface of the reaction mixture is separated and fractionated under diminished pressure. There are obtained besides 200 parts of recovered naphthalene 649 parts of l-chloro-1-methylnaphthalene, that is to say, 61.4.- per cent of the theoretical amount or 83.1 per cent calculated upon the naphthalene consumed. The 1-chloro-l-methylnaphthalene boils at 153 C. under a pressure of 12 mm. mercury, 5 it solidifies in the cold and can be recrystallized) from alcohol. It melts at 31 C. to 32 What we claim is 2+ 1. T e process which comprises reacting 7 formaldehyde upon an aqueous suspension of crystallized naphthalene in the presence of concentrated hydrochloric acid in an amount surpassing that required theoretically for the formation of 1-chloro-1-methylnaphthalene accordingto the equation:

2. The process which comprises reacting formaldehyde of crystallized naphthalene in the presence of concentrated hydrochloric acid at a temperature of about 40 to about C. while stirring-the reacting mixture and while introducing gaseous hydrogen chloride.

3. T e process which comprises reacting formaldehyde upon an aqueous suspension of crystallized naphthalene in the presence of concentrated hydrochloric acid at a temperature of about 60 to about 70 C. While 151 stirring the reacting mixture and While introducing gaseous hydrogen chloride.

4:. The process which comprises suspending 768 parts of naphthalene in 750 parts of an aqueous solution of formaldehyde of 30 per cent strength and 3000 parts of concentrated hydrochloric acid, heating the mixture to 60 to 70 C. while stirring and introducing hydrogen chloride.

In testimony whereof, We afiix our signatures.

GUSTAV REDDELIEN. HANS LANGE. 

